Hillary Clinton's presidential campaign deploys husband Bill very carefully

Keene, New Hampshire: Bill Clinton promised voters in 1992 that they'd be getting "two for the price of one" if they elected him to the White House, a presidential duo of the young Arkansas governor and his Yale Law-educated wife.

Nearly a quarter century later, the duo is back - but not quite the same. As 2016 Democratic front-runner Hillary Clinton fends off a rising challenge from challenger Bernie Sanders, a Vermont senator, her campaign aides are grappling with how best to deploy what she has described as her "not-so-secret weapon."

During campaign swings through early voting states Iowa and New Hampshire, Bill Clinton treaded fastidiously through tightly controlled campaign events. A natural-born chit-chatter, he was not giving interviews. When he stopped to talk with reporters after one recent event, campaign aides turned up the music, making a conversation all but impossible.

His remarks to voters have been relatively subdued: long on history, statistics and nostalgia. He's dodged questions about Sanders and Republican front-runner Donald Trump, who's been baiting the Clinton family with comments about the former president's past sexual improprieties

"I'm not going there," Bill Clinton said on Wednesday, when asked about Sanders at a campaign event in New Hampshire. "I came here to tell people why I thought Hillary should be president and her ideas are better."

While Bill Clinton remains a popular figure among Democrats, some of the key achievements of his administration form the basis of Sanders' critique against his wife, that she's too willing to compromise liberal ideals for political gain.

Sanders has denounced his rival's policies on trade, same-sex marriage, crime and welfare cuts. He's made reinstating Glass-Stegall, a Depression-era banking law repealed under Bill Clinton's administration, a central attack line of his campaign.

Clinton aides say those critiques miss the larger picture of wage growth, job creation and a balanced budget. In a debate last month, Clinton said she would turn to her husband for economic advice.

"He carries a message of peace and prosperity under his presidency and I think a lot of Americans would like to get back to those days," Clinton said in an interview on NBC's "Today Show" on Wednesday.

Bill Clinton has said that he regrets approving the Defense of Marriage Act and the "don't ask, don't tell" policy that banned gays and lesbians from military service. He also has looked back with regret on signing the 1994 crime bill, which led to tougher sentencing for drug offenses.

"I signed a bill that made the problem worse," the former president told an audience at the National Association for the Advancement of Colored People's annual meeting in Philadelphia in July. "And I want to admit it."

On Wednesday in New Hampshire, Bill Clinton detailed the economic growth under his administration, listing statistics on wage growth, the decline in poverty and insurance rates.

He walked voters through Hillary Clinton's policy priorities, stressing the need to invest in infrastructure, renewable energy, small business, college affordability and paid leave. And he sprinkled his remarks with his wife's foreign policy and domestic accomplishments as first lady, New York senator and secretary of state.

"Whatever I say about Hillary's plans, you're entitled to give it a little discount," he said. "But I ought to get some credit for knowing something about how to run the economy."